Temperature dependent weak field Hall resistance in two-dimensional carrier systems

Area of Science:

• Condensed Matter Physics
• Materials Science
• Semiconductor Physics

Background:

• Understanding charge transport in two-dimensional (2D) systems is crucial for developing advanced electronic devices.
• The Hall effect, a key phenomenon in charge transport, provides insights into carrier density and scattering mechanisms.
• Recent experiments have observed unusual temperature-dependent Hall resistance in dilute 2D systems, prompting theoretical investigation.

Purpose of the Study:

• To theoretically investigate the weak-field Hall resistance in 2D systems at low densities and temperatures.
• To explain the nonmonotonic temperature dependence of the 2D Hall coefficient, particularly the decrease observed in dilute 2D hole systems.
• To predict the behavior of the Hall coefficient at higher temperatures based on impurity scattering.

Main Methods:

• Utilizing the Drude-Boltzmann semiclassical transport theory.
• Modeling carrier scattering by screened random charged impurity centers.
• Calculating the weak-field Hall resistance and temperature-dependent 2D Hall coefficient.

Main Results:

• The theoretical model reveals striking nonmonotonicity in the temperature-dependent 2D Hall coefficient for strongly screened systems.
• The study qualitatively explains the experimental observation of decreasing Hall resistance with increasing temperature in dilute 2D hole systems.
• A prediction is made for the eventual increase of the impurity scattering-limited Hall coefficient at higher temperatures.

Conclusions:

• The Drude-Boltzmann theory successfully explains the anomalous temperature dependence of the Hall resistance in certain 2D systems.
• Screened charged impurity scattering plays a critical role in the observed nonmonotonic Hall coefficient behavior.
• Further experimental verification of the predicted Hall coefficient increase at higher temperatures is warranted.